Question: The grades on a language midterm at Santa Rita are normally distributed with $\mu = 85$ and $\sigma = 4.0$. Kevin earned a $92$ on the exam. Find the z-score for Kevin's exam grade. Round to two decimal places.
A z-score is defined as the number of standard deviations a specific point is away from the mean We can calculate the z-score for Kevin's exam grade by subtracting the mean $(\mu)$ from his grade and then dividing by the standard deviation $(\sigma)$ $ { z = \dfrac{x - {\mu}}{{\sigma}}} $ $ { z = \dfrac{92 - {85}}{{4.0}}} $ ${ z \approx 1.75}$ The z-score is $1.75$. In other words, Kevin's score was $1.75$ standard deviations above the mean.